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Localization of TASK and TREK, Two-Pore Domain K+ Channels, in Human Cytotrophoblast Cells

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The Journal of the Society for Gynecologic Investigation: JSGI Aims and scope Submit manuscript

Abstract

Objective

Two-pore domain K+ channels (K2P), an emerging K+ channel subfamily, contribute to setting membrane potential in both electrically excitable and nonexcitable cells and, as such, influence cellular function. The multinucleate syncytiotrophoblast of human placenta, formed from the fusion of mononucleate cytotrophoblast cells, is a transporting epithelium whose function likely depends on the activity of K+ channels. We have therefore investigated the gene expression of two members of this family, TASK and TREK, in cultured human cytotrophoblast cells, and have also investigated protein expression in cytotrophoblast cells and placenta.

Methods

We used reverse transcriptase—polymerase chain reaction (RT-PCR), Western blotting, and immunocytochemistry to investigate the gene and protein expression of TASK and TREK isoforms in both isolated cytotrophoblast cells and term placental tissue.

Results

In cytotrophoblast cells, mRNAs encoding TASK1, 2, 4, 5, and TREK1 were detected, whereas weak or no signals were observed for TASK3 and TREK2. Western blotting for TASK1 in cytotrophoblast cells gave two bands of approximately 78 and 150 kd; TREKÍ gave bands of approximately 90 and 130 kd. TASK1 immunofluorescence in placenta colocalized with cytokeratin-7, a trophoblast-specific marker. TREK1 predominantly stained cells around the villous perimeter and this staining was colocalized with propidium iodide nuclear staining.

Conclusion

Human cytotrophoblast cells from term placenta are a site of expression for various K2P genes, two of which, namely, TASK1 and TREK1, are transcribed into protein.

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Authors and Affiliations

  1. Maternal and Fetal Health Research Centre and Academic Unit of Child Health, University of Manchester, St. Mary’s Hospital, Manchester, UK, Hathersage Road, M13 OJH

    Xilian Bai MSc, Susan L. Greenwood PhD, Jocelyn D. Glazier PhD, Philip N. Baker DM, Colin P. Sibley PhD, Michael J. Taggart PhD & Gregor K. Fyfe PhD

Authors
  1. Xilian Bai MSc
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  2. Susan L. Greenwood PhD
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  3. Jocelyn D. Glazier PhD
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  4. Philip N. Baker DM
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  5. Colin P. Sibley PhD
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  6. Michael J. Taggart PhD
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  7. Gregor K. Fyfe PhD
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Corresponding author

Correspondence to Gregor K. Fyfe PhD.

Additional information

Supported by Tommy’s, the baby charity, and the Wellcome Trust (Grant no. 060997/Z/00).

The authors would like to acknowledge Maureen O’Hara for technical assistance, Dr Peter March for assistance with confocal microscopy, and the efforts of midwives and clinicians in recruiting patients.

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Bai, X., Greenwood, S.L., Glazier, J.D. et al. Localization of TASK and TREK, Two-Pore Domain K+ Channels, in Human Cytotrophoblast Cells. Reprod. Sci. 12, 77–83 (2005). https://doi.org/10.1016/j.jsgi.2004.08.004

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  • DOI: https://doi.org/10.1016/j.jsgi.2004.08.004

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